mjp123gp
Member
I've got a Controllogix system that is doing a MSG Read from an SLC500 PLC and over the past week we have had multiple issues with the MSG timing out(Extended Error code: 16#0000_0204). While the MSG is getting the errors I can ping both IP addresses and they both have under 2ms response times. None of the other MSG instructions in the program are getting errors, just the one PLC. Today when it happened, I noticed the panelview connected to the SLC500 had a message on it that said "16415: arp info overwritten for 0ad3e0e0 by f4:54:33:94:31:c8". The hex address "0ad3e0e0" converts to the IP of the SLC controller that is having the issues and the mac address is a different SLC processor on the other side of the plant. I've checked both processors and the IP configurations are still correct in each of them. I've also done a network scan while this issue was going on to make sure the IP address we are messaging matches the MAC address of the device just incase it was a duplicate IP issue, but all that looks good. The only thing I can see so far that is a little odd to me is the arp message on the panelview.
Any suggestions? I'm not really sure what my next step would be to troubleshoot the issue.
Any suggestions? I'm not really sure what my next step would be to troubleshoot the issue.